Thursday, October 25, 2012

Manual Press Operation

I first built my manual press nearly 40 years ago, and it has occupied a place in my work shop continuously since then.  Some times it just sits there and takes up space.  Other times it is full for days on end and makes me money.  I have posted images of this press before and you can use the search box to find more.

The press is made of 4 x 5" maple beams, 60" long, with 5 Jorgensen 12" veneer press screws per arm. I had a pipe shop supply threaded 3/4" pipes for each end, and I can remove the top cap to lift the upper arm off for some jobs.  I also have other pipes which are longer (32", 48", 60") and I can substitute these pipes to lift the upper arm as high as needed to clear certain projects, like cabinets.

However, since the press screws have only a 12" thread, the effective clamping distance of the screw is about 6" or so, and the upper arm needs to be relatively close to the work to operate properly.

I also have lots of different sizes aluminum sheets which I use for heating the glue.  The actual bed of the press is two sheets of 3/4" plywood, and I place the aluminum on top of that.  To use the press, I pull out the aluminum and prop it up on one end, with a kerosene heater under it.  Using scrap sheets of plywood around the edges, I can create a heat box to trap the heat under the aluminum.  With this method I can heat the press quite rapidly.  When it is ready, I just slide the aluminum back into the press, add some newspaper and place my veneer project face down on the heated caul, making sure the newspaper is in place.

You only glue your project to the aluminum once to learn the importance of two sheets of paper.

To demonstrate how this press can be adapted to certain projects, here is a short video.  This shows Patrice and I working together to press the top of a French Art Deco desk.  This desk is veneered in palm wood which is difficult to work with.  It had dried out and become delaminated over time.  We used a method to rehydrate the animal glue, which involves adding water to the surface of the veneer, waiting a short time, and then adding liquid protein glue (Old Brown Glue) over the entire surface, working it into the cracks and under the veneer as much as possible.

The desk is then placed face side down on the heated press, with paper between the top and the aluminum.  Since it was too large to slide under the clamps, we removed the top arm and replaced it after the desk was in place.  The video shows us reattaching the top arm and then tightening the press clamps in sequence.

We speeded up the video at the end, just to show the process in a short time.  We wish we could work that fast...

video
(Please excuse my French at the end of the video.)

2 comments:

Anonymous said...

looks like a good functional setup. Thanks for the recent uptick in posts. I really enjoy learning about your work & methods

Bob Egbert said...

That a serious press there Patrick. You guys work well as a team.